It is well-know that cancers are the uncontrollable cell proliferation and leukemia is accounted for the highest number of pediatric cancers (20%) in Iran. Thus, the present study was designed to evaluate the cytotoxic effects of Taraxacum syriacum on leukemic cell line (KG-1a). The human leukemic cell line of KG-1a was cultured in the RPMI medium with 10% fetal bovine serum (FBS). Taraxacum syriacum extract was administered on KG-la and normal lymphocytes with different concentrations in different times using the MTT assay and compared with methotrexate as a control positive treatment. Taraxacum syriacum displayed the highest cytotoxic effects on leukemic cells (KG-la) compared with the control (positive treatment and normal lymphocytes). The cytotoxic effect in all treatments increased with elevation concentration of extracts and the lowest and highest toxicity were seen in the 4th and 12th hours after treatment, respectively. Our results showed the high cytotoxic effect of Taraxacum syriacum on leukemic cell lines (KG-1a) and the low toxicity of its effect in normal lymphocyte cells. Therefore, it may be recommended in further investigations performed to evaluate the precise effect of Taraxacum syriacum on the leukemia cell lines.
